Sorry Humsafar.In the Vedas it is called Kamasutra but nowadays it is called, sheeee gnadi baat
None said yet its in vedas or a part of it as per me.
Neither a part of 108 valid upanishads(Part of vedas-Uttar bhaag)
Neither falls in two epic mahakavyas
Neither falls under 6shashtras
Neither falls under recognised samhitas.
Hence it seems not a part of vedas.
Its likely a tantra sutra stuff made in early gupta period or somewhat close to that i cant say exactly.